'fold up' definitions:

Definition of 'fold up'

(from WordNet)
verb
Bend or lay so that one part covers the other; "fold up the newspaper"; "turn up your collar" [syn: fold, fold up, turn up] [ant: open, spread, spread out, unfold]
verb
Become folded or folded up; "The bed folds in a jiffy" [syn: fold, fold up]